package com.nowcoder.community.service;
import com.nowcoder.community.util.RedisKeyUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.connection.RedisStringCommands;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
@Service
public class DataService {
    @Resource
    private RedisTemplate redisTemplate;
    private SimpleDateFormat df=new SimpleDateFormat("yyyyMMdd");
    public void recordUV(String ip){
        String redisKey= RedisKeyUtil.getUVKey(df.format(new Date()));
        redisTemplate.opsForHyperLogLog().add(redisKey,ip);
    }
    //将指定的IP存入UV当中
    
    public long calculateUV(Date start,Date end){
        if(start==null||end==null){
            throw new IllegalArgumentException("参数不能为空！");
        }
        //整理该日期范围内的key
        List<String> keyList = new ArrayList<>();
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(start);
        while (!calendar.getTime().after(end)) {
            String key = RedisKeyUtil.getUVKey(df.format(calendar.getTime()));
            keyList.add(key);
            calendar.add(Calendar.DATE, 1);
        }
        //合并这些数据
        String redisKey =RedisKeyUtil.getUVKey(df.format(start),df.format(end));
        //代表一个时间范围内，有如此多的时间节点
        redisTemplate.opsForHyperLogLog().union(redisKey,keyList.toArray());
        
        // 返回统计的结果
        return redisTemplate.opsForHyperLogLog().size(redisKey);
    }
    //统计指定日期范围内的UV
    
    public void recordDAU(int userId){
        //签到
        String redisKey=RedisKeyUtil.getDAUKey(df.format(new Date()));
        redisTemplate.opsForValue().setBit(redisKey,userId,true);
    }
    //将指定的用户计入DAU

    // 统计指定日期范围内的DAU
    public long calculateDAU(Date start,Date end){
        if(start==null||end==null){
            throw new IllegalArgumentException("参数不能为空!");
        }
        //整理该日期范围内的key
        List<byte[]>keyList=new ArrayList<>();
        Calendar calendar=Calendar.getInstance();
        calendar.setTime(start);
        while(!calendar.getTime().after(end)){
            String key=RedisKeyUtil.getDAUKey(df.format(calendar.getTime()));
            keyList.add(key.getBytes());
            calendar.add(Calendar.DATE,1);
        }
        //统计聚合结果--or运算 
        return (long) redisTemplate.execute(new RedisCallback() {
            @Override
            public Object doInRedis(RedisConnection connection) throws DataAccessException{
                String redisKey = RedisKeyUtil.getDAUKey(df.format(start), df.format(end));
                connection.bitOp(RedisStringCommands.BitOperation.OR,
                        //做完运算之后将结果保存到redisKey.getBytes()
                        redisKey.getBytes(), keyList.toArray(new byte[0][0]));
                return connection.bitCount(redisKey.getBytes());
            }
        });
    }
}
